1. Field of the Invention
The present invention relates to differential assemblies, and more particularly to a differential assembly for motor vehicles, having a single-piece open differential case adjustably supported within an axle housing through a pair of opposite differential mounting members.
2. Description of the Prior Art
Conventionally, differentials well known in the prior art, are arranged in a power transmission system of a motor vehicle to allow a pair of output shafts operatively coupled to an input shaft to rotate at different speeds, thereby allowing the wheel associated with each output shaft to maintain traction with the road while the vehicle is turning. Conventional differentials include a differential case defining a gear chamber, and disposed therein, a differential gear set including at least one input pinion gear, and a pair of output side gears non-rotatably coupled to corresponding axle shafts. Such a device essentially distributes the torque provided by the input shaft between the output shafts. This type of differentials is known in the art as an open differential, i.e. a differential where movements of its various internal components are not restricted in any significant fashion.
The open differentials are unsuitable in slippery conditions where one wheel experiences a much lower coefficient of friction than the other wheel. In such a condition, limited slip differentials are employed that usually include at least one frictional clutch pack typically disposed between the side gear and an adjacent surface of the gear case, such that the clutch pack is operable to limit relative rotation between the gear case and the one side gear.
Conventionally, the differential assemblies comprise a differential case having two complementary halves. A differential pinion shaft is disposed between the two halves bolted together.
The conventional differential assemblies are relatively complex and expensive in manufacturing requiring narrow tolerance zone, and labor extensive in assembling. Furthermore, assembling of the differentials in the limited slip configuration requires laborious process of gauging and selecting the appropriate friction clutch pack.
Thus, there is a need for a differential assembly that is simple, compact and inexpensive to manufacture that includes a simplified differential case that may be used in both open and limited slip configurations.
The present invention provides a simplified differential assembly having single-piece hollow open-ended differential case and a free-floating differential gear mechanism mounted therewithin. The differential case is provided with a plurality of axial grooves formed on an inner peripheral surface of the differential case and extending between opposite open ends thereof. The differential gear mechanism includes a pinion shaft rotatably supporting a plurality of pinion gears in a free-floating manner, and adapted to drivingly engage the axial grooves of the differential case. The differential gear mechanism further includes a pair of opposite side gears in meshing engagement with the plurality of pinion gears to permit differential rotation thereof.
The differential case is axially adjustably supported within an axle housing by means of two opposite mounting members. The mounting members are rotatably supporting the differential case at the opposite ends thereof through anti-friction roller bearings.
The single-piece differential case in accordance with the present invention may be used for differential assemblies in both open and limited slip configurations.
The first exemplary embodiment of the present invention discloses an open differential assembly further including a thrust washer positioned between the side gear and the roller bearing.
The second exemplary embodiment of the present invention discloses a limited slip differential assembly further including a limited slip mechanism in the form of at least one friction clutch pack disposed between the side gear and the roller bearing. The friction clutch pack includes a number of alternating outer friction plates non-rotatably coupled to the axial grooves formed on the inner peripheral surface of the differential case, and inner friction plates splined to the side gear.
Therefore, the locking differential assembly in accordance with the present invention provides a simple, compact, easy to assemble and inexpensive differential assembly that may be used in both open and limited slip configurations.